CarMax Beats Earnings Estimates as Revenue Jumps 20%. The Stock Rises. — Barrons.com

By Kit NortonShares of CarMax rose Tuesday after the used-car retailer posted fiscal second-quarter earnings that topped analysts' estimates.CarMax stock advanced 3.9% to $58.74 in premarket trading on Tuesday after ending Monday down 1.2%. Carvana rose 0.5%. AutoNation was flat and Group 1 Automot…